iOS蓝牙相关

蓝牙写数据权限问题
根据蓝牙writeCharacteristic.properties判断，CBCharacteristicWriteWithoutResponse还是CBCharacteristicWriteWithResponse

[_peripheral writeValue:data forCharacteristic:_writeCharacteristic type:CBCharacteristicWriteWithoutResponse];
[_peripheral writeValue:data forCharacteristic:_writeCharacteristic type:CBCharacteristicWriteWithResponse];

CBCharacteristicWriteWithResponse会响应CBPeripheral的代理方法

/*!
 *  @method peripheral:didUpdateValueForCharacteristic:error:
 *
 *  @param peripheral       The peripheral providing this information.
 *  @param characteristic   A <code>CBCharacteristic</code> object.
 *  @param error            If an error occurred, the cause of the failure.
 *
 *  @discussion             This method is invoked after a @link readValueForCharacteristic: @/link call, or upon receipt of a notification/indication.
 */
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(nullable NSError *)error;